It seems like your request, which is a SOAP XML, has an error. You may want to provide more info: what API/SDK do you use? what method call did you issue? what parameters did you provide? A code snippet would be helpful.
Steve, author of VMware VI and vSphere SDK, creator of VI/vSphere Java API http://www.doublecloud.org
Steve JIN
Author of VMware VI and vSphere SDK; Creator of open source VI Java API (http://vijava.sf.net); Blogger at http://www.doublecloud.org